The present invention relates to new peptidic compounds analogous to Distamycin A, to a process for their preparation, to pharmaceutical compositions containing them and to their use as therapeutic agents.
Distamycin A is an antibiotic substance with antiviral and oncolytic properties, having a polypyrrole framework (Nature 203, 1064 (1964); J. Med. Chem. 32, 774-778 (1989)).
Several compunds analogous to Distamycin A and derivatives thereof are known in the art.
The international patent application WO 97/43258, in the name of the applicant, discloses acryloyl distamycin derivatives wherein the amidino moiety is replaced by different nitrogen-containing ending groups such as, for instance, cyanamidino, N-methylamidino, ethylguanidino, amido, amidoximo, nitrile and the like.
Distamycin derivatives wherein at least one pyrrole ring of the aforementioned polypyrrole framework is substituted by an imidazole or pyrazole ring are also reported in the literature.
See, for a general reference, Anti-Cancer Drug Design 8, 173-192 (1993); J. Am. Chem. Soc. Vol. 114, 5911-5919 (1992); Anti-Cancer Drug Design 6, 501-517 (1991); patent applications EP-A-0246868 and WO 96/05196, both in the name of the applicant.
It has now been found that a new class of distamycin derivatives as defined hereinunder, wherein at least one ring of the polypyrrole framework is other than pyrrole, the formyl group is substituted by an acryloyl moiety and the amidino group is substituted by different nitrogen-containing ending groups, shows valuable biological properties.
Therefore, the present invention provides compounds which are acryloyl substituted distamycin derivatives of formula 
wherein:
n is 2, 3 or 4;
m is 1 or 2;
X and Y are the same or different and are selected, independently for each heterocyclic ring of the polyhetherocyclic chain, from N and CH;
R1 and R2, which are the same or different, are selected from hydrogen, halogen, and C1-C4 alkyl;
R3 is hydrogen or halogen;
B is selected from 
wherein R4, R5, R6, R7, R8, R10, R11 and R12 are, independently from each other, hydrogen or C1-C4 alkyl; and R9 is hydrogen or hydroxy;
or a pharmaceutically acceptable salt thereof;
provided that
a) at least one of R4, R5 and R6 is alkyl;
b) at least one of the heterocyclic rings within the polyheterocyclic chain is other than pyrrole; and
c) X and Y are not both N for the same heterocyclic ring.
The present invention includes within its scope also all the possible isomers covered by the compounds of formula (I), both separately and in admixture, as well as the metabolites and the pharmaceutically acceptable bio-precursors (otherwise known as pro-drugs) of the compounds of formula (I).
In the present description, unless otherwise specified, the term alkyl includes straight or branched alkyl, for instance C1-C4 alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl; the term halogen includes fluorine, chlorine, bromine and iodine.
Preferably, the alkyl groups are selected from methyl and ethyl and the halogen atoms are selected from fluorine, chlorine or bromine.
Pharmaceutically acceptable salts of the compounds of formula (I) are the salts with pharmaceutically acceptable, inorganic or organic, acids. Examples of inorganic acids are hydrochloric, hydrobromic, sulphuric and nitric acid; examples of organic acids are acetic, propionic, succinic, malonic, citric, tartaric, methanesulfonic and p-toluenesulfonic acid.
As above reported, X and Y are selected, independently for each heterocyclic ring of the polyheterocyclic chain, between N and CH. This means that within the compounds of formula (I) and for different heterocyclic rings, X can be either N as well as CH; the same applies for Y provided that X and Y are not contemporaneously N for a single heterocycle.
Examples for the said heterocycles are pyrrole, pyrazole and imidazole.
A preferred class of compounds according to the present invention is represented by the compounds of formula (I) wherein R4, R5, R6, R7, R8, R10, R11 and R12 are, independently from each other, hydrogen, methyl, or ethyl.
Even more preferred are the compounds of formula (I) wherein
n is 3 or 4;
m is 1;
R1 and R2 are hydrogen;
R3 is chlorine or bromine;
B is selected from 
wherein R4, R5, R6, R7, R8, R10, R11 and R12 are, independently from each other, hydrogen or methyl; R9 is hydrogen.
Another class of preferred compounds of formula (I) are those wherein the acrylamido moiety is directly linked to a pyrazole or imidazole ring.
Examples of specific compounds according to the present invention, especially in the form of salts, preferably with hydrochloric acid, are the following:
(1) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propioncyanamidine;
(2) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(3) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(4) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,Nxe2x80x2-dimethylamidine;
(5) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,Nxe2x80x2-dimethylamidine;
(6) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,N,Nxe2x80x2-trimethylamidine;
(7) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamide;
(8) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamide;
(9) 2-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(10) 2-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(11) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propyl-N,N-dimethylamine;
(12) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(13) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(14) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-O-methylamidoxime;
(15) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-O-methylamidoxime;
(16) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionitrile;
(17) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionitrile;
(18) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propioncyanamidine;
(19) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(20) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,Nxe2x80x2-dimethylamidine;
(21) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,N,Nxe2x80x2-trimethylamidine;
(22) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido propionamide;
(23) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamide;
(24) 2-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(25) 2-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-chloroacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(26) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propyl-N,N-dimethylamine;
(27) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(28) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-chloroacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(29) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-O-methylamidoxime;
(30) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-chloroacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-O-methylamidoxime;
(31) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido) propionitrile;
(32) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(33) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(34) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,Nxe2x80x2-dimethylamidine;
(35) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,N,Nxe2x80x2-trimethylamidine;
(36) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamide;
(37) 2-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(38) 2-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(39) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(40) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionitrile;
(41) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propioncyanamidine;
(42) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamide;
(43) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,N-dimethylamine;
(44) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-O-methylamidoxime;
(45) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionitrile;
(46) 3-(1-methyl-3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrazole-5-carboxamido)propion-N-methylamidine;
(47) 3-(1-methyl-3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrazole-5-carboxamido)propion-N,Nxe2x80x2-dimethylamidine;
(48) 2-(1-methyl-3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrazole-5-carboxamido)ethylguanidine;
(49) 3-(1-methyl-3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrazole-5-carboxamido)propionamidoxime;
(50) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)imidazole-2-carboxamido)propion-N-methylamidine;
(51) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)imidazole-2-carboxamido)propionamide;
(52) 2-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)imidazole-2-carboxamido)ethylguanidine;
(53) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)imidazole-2-carboxamido)propionamidoxime;
(54) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(55) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,Nxe2x80x2-dimethylamidine;
(56) 2-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(57) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(58) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionitrile;
(59) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propioncyanamidine;
(60) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(61) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(62) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,Nxe2x80x2-dimethylamidine,
(63) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,N,Nxe2x80x2-trimethylamidine;
(64) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamide;
(65) 2-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(66) 2-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(67) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(68) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-chloroacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(69) 3-(1-methyl-4-(1-methyl-4-(1-methyl-3-(xcex1-bromoacrylamido)pyrazole-5-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionitrile;
(70) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propioncianamidine;
(71) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamidine;
(72) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,Nxe2x80x2-dimethylamidine;
(73) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N,N,Nxe2x80x2-trimethylamidine;
(74) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamide;
(75) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-N-methylamide;
(76) 2-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)ethylguanidine;
(77) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrcle-2-carboxamido)pyrrole-2-carboxamido)propion-N,N-dimethylamine;
(78) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionamidoxime;
(79) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propion-O-methylamidoxime;
(80) 3-(1-methyl-4-(1-methyl-4-(1-methyl-4-(xcex1-bromoacrylamido)imidazole-2-carboxamido)pyrrole-2-carboxamido)pyrrole-2-carboxamido)propionitrile.
The compounds of the present invention can be prepared according to one of the following processes, which comprise:
(a) reacting a compound of formula: 
wherein n, m, X, Y and B are as defined above;
p is 0 or 1;
with a compound of formula: 
wherein R1, R2, R3, X, Y and p are as defined above;
Z is hydroxy or a leaving group;
or:
(b) when B is equal to xe2x80x94Cxe2x89xa1N, reacting a compound of formula: 
wherein n, m, R1, R2, R3, X and Y are as defined above;
with succinic anhydride; and
(c) if desired, converting a compound of formula (I) into a pharmaceutically acceptable salt thereof.
In the compounds of formula (III), Z is hydroxy or a suitable leaving group selected, for instance, among chloro, 2,4,5-trichlorophenoxy, 2,4-dinitro-phenoxy, succinimido-N-oxy, imidazolyl group, and the like.
The reaction of process (a) as above between a compound of formula (II) and a compound of formula (III) can be carried out according to known methods, for instance those described in the aforementioned EP-A-246,868 and WO 96/05196.
It is clear to the man skilled in the art that when preparing the compounds of formula (I) according to the process object of the present invention, optional amino groups, i.e. R10 and/or R11 of the compound of formula (II) equal to hydrogen, need to be properly protected according to conventional techniques, so as to avoid unwanted side reactions.
Likewise, the conversion of the said protected amino group into the free amine may be carried out according to known procedures. See, for a general reference, J. Org. Chem. 43, 2285, (1978); J. Org. Chem. 44, 811 (1979); J. Am. Chem. Soc. 78, 1359 (1956); Ber. 65, 1192 (1932); and J. Am Chem. Soc. 80, 1154, (1958).
The compounds of formula (II) may be prepared by converting the compounds of formula (V) 
wherein T is a nitro group or an amino group properly protected with a group such as, for instance, t-butyloxycarbonyl, triphenylmethyl or, preferably, carbobenzyloxy or formyl; X, Y, B, n, m and p are as defined above; into the desired amino derivative of formula (II).
The conversion of the nitro group into amino group may be carried out according to known procedures such as, for instance, hydrogenation under hydrogen pressure in the presence of suitable catalysts, e.g., palladium on charcoal, into a suitable solvent such as dioxane, methanol, ethanol and mixtures thereof, at room temperature.
The compounds of formula (V) wherein B is other than 
can be obtained, in their turn, from the compounds of formula: 
wherein T, X, Y, n, p and m are as defined above; by using:
(i) H2Nxe2x80x94CN, so obtaining a compound of formula (V) having B equal to: 
(ii) H2Nxe2x80x94OR12 wherein R12 has the above reported meanings, so obtaining a compound of formula (V) having B equal to: 
(iii) H2Nxe2x80x94NH2, so obtaining a compound of formula (V) having B equal to: 
(iv) HNR4R5, so obtaining a compound of formula (V) having B equal to: 
and then optionally with H2NR6, so obtaining a compound of formula (V) having B equal to: 
wherein R4, R5, and R6 are as defined above;
(v) succinic anhydride, so obtaining a compound of formula (V) having B equal to xe2x80x94Cxe2x89xa1N;
(vi) water in an alkaline medium, so obtaining a compound of formula (V) having B equal to xe2x80x94COxe2x80x94NR7R8 wherein R7 and R8 are both hydrogen;
(vii) HNR7R8, so obtaining a compound of formula (V) having B equal to: 
and then with water in an alkaline medium, so obtaining a compound of formula (V) having B equal to xe2x80x94COxe2x80x94NR7R8, wherein R7 and R8 are as defined above.
The reaction between a compound of formula (VI) and one of the reactants as set forth in points (i)-(vii) as above can be carried out according to known methods, for instance those reported in WO97/43258; Chem. Revs. 1961; 155; J. Med. Chem. 1984, 27, 849-857; Chem. Revs. 1970, 151; and xe2x80x9cThe Chemistry of Amidines and Imidatesxe2x80x9d, edited by S. Patai, John Wiley and Sons, N.Y. (1975).
Alternatively, the compounds of formula (V) wherein B is other than 
can be prepared from a compound of formula: 
wherein n, p, X, Y, T and Z are as defined above, by reaction with a compound of formula: 
wherein m is as defined above and B is selected from: 
wherein R4, R5, R6, R7, R8, R9, R10, R11 and R12 are as defined above.
Finally, the compounds of formula (V) wherein B is other than 
can be prepared through the so-called Pinner reaction, by reacting a compound of formula (V) wherein B is equal to CN with a suitable amino compound as set forth above under points (i), (ii), (iii) or (iv).
Also the compounds of formula (III) are known or easily prepared according to conventional methods.
See, for a general reference, WO96/05196; J.C.S. 1947-1032 and JACS 62, 3495 (1940).
The reaction of process (b) is carried out according to the method reported in WO 97/43258.
The compounds of formula (IV), (VI), (VII) and (VIII) are known compounds, or may be obtained by known methods (see, for a general reference, Tetrahedron, 34, 2389-2391, 1978; J. Org. Chem., 46, 3492-3497, 1981; J. Org. Chem., 52, 3493-3501, 1987; WO96/05196 and WO97/43258.
The optional conversion of a compound of formula (I) into a pharmaceutically acceptable salt, as well as the preparation of a free compound starting from a salt, may be carried out by known standard methods.
Well known procedures such as, e.g., fractional crystallization or chromatography, may also be followed for separating a mixture of isomers of formula (I) into the single isomers.
The compounds of formula (I) may be purified by conventional techniques such as, e.g., silica gel or alumina column chromatography, and/or by recrystallization from an organic solvent such as, e.g., a lower aliphatic alcohol, e.g. methyl, ethyl or isopropyl alcohol, or dimethylformamide.
The compounds of the invention show cytotoxic properties towards tumor cells so that they can be useful as antineoplastic agents, e.g. to inhibit the growth of various tumors such as, for instance, carcinomas, e.g. mammary carcinoma, lung carcinoma, bladder carcinoma, colon carcinoma, ovary and endometrial tumors. Other neoplasias in which the compounds of the invention could find application are, for instance, sarcomas, e.g. soft tissue and bone sarcomas, and the hematological malignancies such as, e.g., leukemias.
The antitumor activity of the compounds of formula (I) was evaluated in vitro by cytotoxicity studies carried out on murine L1210 leukemia cell. Cells were derived from in vivo tumors and established in cell culture. Cells were used until the tenth passage. Cytotoxicity was determined by counting surviving cells after 4 hours treatment and 48 hours growth in drug-free medium.
The percentage of cell growth in the treated cultures was compared with that of controls. Doses inhibiting 50% of the cellular growth in respect to controls, expressed as ID50 values, were calculated on dose-response curves.
The compounds of the invention can be administered by the usual routes, for example, parenterally, e.g. by intravenous injection or infusion, intramuscularly, subcutaneously, topically or orally.
The dosage depends on the age, weight and conditions of the patient and on the administration route.
For example, a suitable dosage for administration to adult humans may range from about 0.05 to about 100 mg pro dose 1-4 times a day.
The pharmaceutical compositions of the invention contain a compound of formula (I) as the active substance, in association with one or more pharmaceutically acceptable excipients.
The pharmaceutical compositions of the invention are usually prepared following conventional methods and are administered in a pharmaceutically suitable form.
For instance, solutions for intravenous injection or infusion may contain sterile water as a carrier or, preferably, they may be in the form of sterile aqueous isotonic saline solutions.
Suspensions or solutions for intramuscular injections may contain, together with the active compound, a pharmaceutically acceptable carrier, e.g. sterile water, olive oil, ethyl oleate, glycols, e.g. propylene glycol and, if desired, a suitable amount of lidocaine hydrochloride.
In the form for topical application, e.g. creams, lotions or pastes for use in dermatological treatment, the active ingredient may be mixed with conventional oleaginous or emulsifying excipients.
The solid oral forms, e.g. tablets and capsules, may contain, together with the active compound, diluents, e.g. lactose, dextrose, saccharose, cellulose, corn starch and potato starch; lubricants, e.g. silica, talc, stearic acid, magnesium or calcium stearate, and/or polyethylene glycols; binding agents, e.g. starches, arabic gums, gelatin, methylcellulose, carboxymethyl-cellulose, polyvinylpyrrolidone; disaggregating agents, e.g. a starch, alginic acid, alginates, sodium starch glycolate; effervescing mixtures; dyestuffs; sweeteners; wetting agents, for instance, lecithin, polysorbates, laurylsulphates; and, in general, non-toxic and pharmacologically inactive substances used in pharmaceutical formulations. Said pharmaceutical preparations may be manufactured in a known manner, for example by means of mixing, granulating, tabletting, sugar-coating, or film-coating processes.
Furthermore, according to the present invention, there is provided a method of treating tumors in a patient in need of it, comprising administering to the said patient a composition of the invention.
The following examples illustrate but do not limit the invention.
The abbreviations DMF and DMSO-d6 stand for dimethylformamide and deutero-dimethylsulfoxide, respectively.